1. Field of the Invention
Multi-wheeled cycles, or what is commonly known as scooters on the market today typically comprise a platform supported on a front wheel that may be steered by a solid fixed or foldable handle bar, and a back wheel, some including a dual rear wheel axle. The user propels the scooter by simply pushing one foot on the pavement or ground, providing driving thrust. Smaller versions of this standard of recent have become quite popular. However, there are many scooters, even in the early 20th century, that have attempted to put pedal driving means with this above arrangement as a more convenient alternative to the foot thrust drive, and manually power the scooter, instead, by pedal motive force. This pedal driving scooter, vehicle, is the field of the particular invention.
2. Prior Art
Many structures for scooters have been invented that propel the scooter using various drive systems, for example U.S. Pat. No. 4,186,934 describes a scooter propulsion system having a ratchet drive. Even quite earlier were many attempts at devising a pedal drive means that uses a single ratchet wheel drive, such as in U.S. Pat. No. 1,750,187, combined with a slotted drive arm affixed to a tilting “see-saw” type main drive pedal. A ratchet drive can be found in U.S. Pat. No. 6,270,102 B1 that includes the unidirectional mechanism coupled with a gear train that links a chain and sprocket drive to the rear wheel.
Another clever ratchet mechanism uses reciprocating ratcheting rack gears on the end of pedal levers, as shown in U.S. Pat. No. 1,601,249. Another of this type, but more elaborate is found in U.S. Pat. No. 2,723,131; and still similarly in U.S. Pat. Nos. 4,124,222 and 6,857,648. A double pedal design is described in U.S. Pat. No. 1,440,372 that uses a sector gear drive and double wheel rear axle, as the present invention may also employ. A recent patent that uses a sector ratchet gear of similar structure and drive is in U.S. Pat. No. 6,688,624. The ratchet in U.S. Pat. No. 2,436,199 is actually within the sprocket gear itself. Still another version of the ratchet type drive uses cables or chains with drive sprockets or gears that often include a spring at one end to retract the chain or cable, after the pedal pulls it around the sprocket, thus “pulse-driving” the wheel. These types are found in U.S. Pat. Nos. 3,544,996 and 2,035,835. More recent versions of this type are disclosed in U.S. Pat. Nos. 4,379,566 and 7,044,488. Other early versions of this is found in U.S. Pat. No. 1,653,889 and also in the Bergen U.S. Pat. No. 2,118,640 and Whitehouse U.S. Pat. No. 3,175,844, which use the cable and/or chain plus ratchet combination drive, as does the more recent U.S. Pat. No. 5,192,089 with an even more elaborate mechanism depicted in U.S. Pat. No. 5,368,321 Some more recent patents have improved upon the cable and ratchet clutch mechanisms by using smaller and shorter multi-linkages to the one-way ratchet and add a back “kick-pedal” to pull out such cable and or chain driving, as in U.S. Pat. Nos. 3,992,029, 4,761,014, Design U.S. Pat. Nos. D582,991, 6,796,570, and 7,487,987, which uses a forward kick pedal and two wheels at the back of the scooter.
These above systems, including that in U.S. Pat. No. 6,716,141 which uses a chain and a cable and a spring, plus the one-way ratchet, all are dependent upon a uni-directional ratchet, or one-way drive mechanisms, which simply are an inefficient way to transfer motion to the drive wheel or wheels. These above discussed patents and several other ratchet type drive mechanisms similar to them do not and cannot drive the wheels in a continuous cycloidal-drive manner. Since, as the cable or chain is fully extended as the pedal drives downward, the cable is spooled out from its uni-directional drive motion on the wheel in a linear and not cycloidal motion, as would be in a linkage or crank bar type drive, as in the present invention. The disadvantage evident in these systems is an “over-running” of the pedal user's motion as he tries to catch up with the increased speed of the scooter from the previous stroke, with a new, now faster stroke, on the next downward stroke of the other pedal.
A good example that may illustrate this linear, rather than cycloidal drive motion, is the old trigger-squeeze toy spark guns—Once the trigger was squeezed to spin the fly wheel sparking stone to brush it against the flint inside at a high rate, then another squeeze at a normal speed trigger pull squeeze would not help contribute speed until the wheel slowed down enough to add another pulse of rotational or torque force that would catch up to the stone wheel actual speed again. So, the ratcheting trigger or the toy spark gun only provides a “pulse-type” motion drive, as would function similarly in the above scooters and cycles that use the ratchet type over-running clutches or one-way clutches or bearings. Then, at the end of the cable maximum extension point right when the cable is beginning to recoil on the ratchet take up spool and wheel, precisely at that point, there is a linear, sharp, non-cycloidal reverse as the recoil stage starts to put drive motion back in, but only at the point the speed of the driven wheel, creating in each cycle an initial “torque-less” point, this energy being wasted motion by the user's foot stroke down on the pedals, until the linear speed catches up with rotational motion of the driven wheel.
It is to be noted that the human body, in nearly all of the motion of its various members, arms and legs particularly, moves in a cycloidal (a continuous, rolling, rotary motion) motion, thus making the above described linear drive nature of the cable and chain recoil one-way clutch drives not as appealing to a cycle user. Even though the user of the present invention is primarily going linearly up and down on the pedals, the “timing” is still cycloidal as to continuous dive motion throughout the upward and downward pedal strokes. Hence, bicycles have never really been surpassed in their mechanical efficiency, since bicycle pedaling this cycloidal pedal motion that corresponds to and is conducive to the same human bodily kinematics natural design.
Still, other scooters or cycles use lever systems that drive rotational torque direct to the driven wheel, or the comprise intervening gear or sprocket and drive means, and instead use linkage drives to effect rotary motion to the wheels. U.S. Pat. No. 5,224,724 discloses a scooter having a simple harmonic drive that is driven by a single see-sawing type platform that is spring biased under its distal end. Linkage levers on one side of scooter connect directly to the back wheel and drive in a harmonic motion. The disadvantage of this drive arrangement, though it has minimal and low-cost drive structure, is that the back wheel's rotational momentum is necessary to stay continuous to keep the linkage from binding. In other words, the user must always be see-sawing up and down at all times the back wheel is rotating—There is no one-way ratchet in the back wheel, and if there were included one, it is believed the device could not function, as lever arms 44, and 34, respectively, would bind over the top dead center positions back wheel axle 36, as shown in FIG. 1, FIG. 4 and FIG. 5.
Another linkage arm drive system in a scooter is described in U.S. Pat. No. 1,558,851 in which a similar single arm see-sawing system, using a three bar linkage drives a sprocket and chain, further driving a sprocket on the back wheel. As in the '724 patent above, though, the back wheel's rotational momentum is necessary to stay continuous to keep the linkage from binding. U.S. Pat. No. 6,648,353 includes sliding pedals that roll at one end on adjustably inclined rails and are linked to lever arms at their opposite ends, said levers arms drive a similar sprocket and chain for the back wheel, as in the '851 patent. Likewise, US Pat. Application 2003/0025293 A1 reveals even a simpler direct drive linkage that also uses the similar sliding drive as the '353 patent, but uses pins in slots, on the reciprocating pedals. Another patent similar to the '851 patent also comprises a see-saw platform, but instead of using a sprocket and chain, uses a gear set to drive the back wheel. Again, it, as well as the '351 patent and '293 application has the same limitations as both of the above discussed patents, in that the back wheel cannot rotate independently of the of the see-sawing platform motion.
It is appropriate to discuss bicycle prior art, in that U.S. Pat. Nos. 4,574,649; 4,630,839; 4,666,173; 4,666,174; 4,227,712; 4,421,334; 3,759,543; 4,574,649; 5,335,927; 5,121,654 all use the type of one-way clutches and similar drive mechanisms discussed above, but on wheeled cycles with seats, that are basically bicycles. Again, like the above scooters that employ the same reciprocating chain and cable drive mechanisms, they have the same shortcomings. As to its uniqueness, U.S. Pat. No. 5,351,575 uses a pumping system that also employs the one-way clutches in a user-seated cycle. So, the present invention may use any sized wheels, in the range of scooters with three or four inch diameters to large diameters up to 27 inches or more and include a seat, also, therefore making the such art relevant.
Other relevant bicycle art is “large-wheeled” scooters and the frames for such, as are described and illustrated in U.S. Pat. Nos. 5,992,864 and 5,470,089, both structures having equal size front and back wheels, U.S. Pat. No. 5,899,474 having far smaller back wheel than front wheel.
A patent with a portion of its structure closer in form to the invention disclosed herein is found in U.S. Pat. No. 1,477,544, wherein a dual pedal drive is also articulated to a two bar linkage at each pedal that is used to drive a back wheel, or wheels, by means of a toothed member. However, it possesses a limited structure, and thus resulting limited function, because it lacks many critical mechanical advantages of the invention, including elements of safety, as discussed in the following, where the '544 Patent reads on line 52:
“ . . . screwed to the underside of each of the pedal boards 9, 10. To the shaft 15 is also fixed the sprocket 20 . . . . ”
By the above clear statement, the '544 patent is directly connecting to back-wheel drive sprocket to the back wheel drive shaft, with no intervening free-wheeling clutch, aka., one-way clutch, inside the hub. This is in direct contrast to such clutch having to be included in the present invention. It is moreover highly relevant that if the '544 patent included a one-way clutch in its wheel hub, instead of directly attaching the sprocket to the back wheel shaft, as it does [and the fact is that the inventor had prior art access to a clutch coaster (one way clutch or ratchet, or freewheel) wheel for cycles at least 12 years before, disclosed in the 1922 U.S. Pat. No. 959,509]. It is then argued that if the '544 Patent included a freewheeling rear wheel, as in the present invention, that upward and downward motions of the pedals would lock up as the pedals bottomed out on either side, and further, the “pedicycle's” drive links could even dangerously reverse direction, since they then would not be able to depend on the back wheel's momentum to keep them in cyclical motion, because the clutch would render the pedal motionless during pedal idling, and unable to advance the drive spindle/shaft because of over top center lock-down thereat, rendering the drive system inoperable, further explained in the following discussion. These are the same limitations that the U.S. Pat. No. 5,224,724 possesses, as discussed previously.
This serious shortcoming becomes readily apparent to one skilled in the present art, once considering '544's illustrations, that '544's linkage structure maintains the pivot or drive link located on the pedal arm directly above (exactly over top dead center) of the main drive sprocket spindle shaft. In doing so, a direct, necessarily continuous drive relationship, both backward and forward directions, is made permanently with the back wheel in order for the cycle to function. It is evident to one skilled in the art that the pedicyle requires the momentum of the back wheel to continually rotate together with the drive sprocket at all times so as to rotate the cranks 17 and links 19 around the drive sprocket, and this being further necessary in order to maintain the pedals' up and down cycle action. Thus, dependency on the momentum of back wheel and for maintaining continuous rotary motion between the wheel and sprocket is a serious limitation of the pedicycle, resulting in the inherent disadvantages and even dangers to the cycle rider.
Moreover, the inventor states: “ . . . In this way any up and downward movement of the pedals 9, 10, is transformed in a continuous rotary movement of the rear wheel of the pedi-cycle.”
In the present invention in its “free-wheeling” or one-way clutch/ratchet wheel, the clearest mechanical drive distinction and mechanical output, with respect to the '544 patent is made, since a user can and may indeed want to “ratchet or cycle” up and down one pedal of one side—while the other pedal side moved up and down without—making any continuous rotary driving motion to the wheel. This is important in reference to the present invention, for instance, because of a rider needing a high angle “lean-in” curving turn ratio and wanting to avoid spragging the low pedal side on the ground, or simply to exercise one leg, or even “ratchet-drive” by going up and down small linear distances on the pedals (not doing compete cycloidal cycles) to drive less aggressively as one would do “meandering” on bicycle pedals back and forth in the same manner. Thus, “some”, even much, motion of the opposite, non-driving pedal motion could be effected with the present invention, as distinctively different than the '544 patent.
It is further clear to one skilled in the art, as regards patent 544, that the structure of the pedals are in exact synchronized opposite continuous motion-position, at all times, with no possibility or option for the cycle rider upon the pedals of having idling rest or non motion with respect to continuous rear wheel motion. In other words, the motion of the pedals can never be independent of the motion of the wheel. Also, due to this mechanical limitation, the cyclist has no stability to start the cycle going with one leg on a pedal and one leg pushing off the ground. If the user tries to push the cycle, he is forced to operate and negotiate the pedicycle's moving pedals, perhaps to the point of injury to the feet or shins, while the pedals are reciprocating up and down in motion at all times. Thus, the user is limited if wishing to push-with-foot and start scooter.
The user would obviously become stressed and fatigued by this unyielding, continuous pedal motion, even once upon and riding the cycle. This structural limitation is not only undesirable for purposes of stability and ease of starting, but as well as limiting the variety of experiences of safe, easy braking, jumping, wheelies, pitched turning and trick riding. The present invention offers a drive system and structure that offer various modifications to enhance the user's experience, and can employ many different kinds of brakes to stop the cycle safely, as well. However, the method of slowing or stopping the art of the '544 patent is plainly the action of the user's legs forcing downward and “retraining” the pedals' rapid reciprocating action—which could be truly hazardous to the rider, especially if traveling down a hill in which much momentum and speed has already been gained. It is reasonable to conclude from this fact that is the reason why no brakes are shown in the '544 structure and cycle system—because the cycle is slowed and stopped according to the above method.
Another disadvantage of the “544 patent is that there is no way to include a change of gear system, as would be, for example, the commonly employed sprocket and derailleur system prevalent in bicycles, since a structure that can support a freewheeling back wheel is not disclosed. Since the present invention's different linkage structure yet maintains a similar '544 pedals' pivot or drive pin located on the pedal arms it must be emphasized that such pivot, crank or drive pin is not directly above—but offset, (either in front of or behind, but not over top dead center) with respect to the main drive sprocket spindle shaft, unlike the '544 patent. Contrary to the '544 patent, the present invention does not require a direct, continuous drive relationship, in both backward and forward drive directions, with the back wheel, as does the '544 patent. However, in the present invention, when one pedal arm is all the way down, the opposite pedal's said crank pin is already beyond full up (beyond top dead center of the said drive spindle) position, thus ensuring continuous rotation of the drive system is sustained independently of the back drive wheel's continuous rotational momentum being necessary to keep the pedals from jamming or locking or reversing at the joints of the said first and second two-bar linkages. This is not true in the '544 patent.
Prior to 1922 (date of the '544 patent), freewheeling clutches for cycle wheels have been established, clearly demonstrating that the '544 patent had access to ratchet mechanisms for scooter back wheel hubs, if desired. However, the above discussion demonstrates that patent '544's drive structure does not, nor cannot, support a ratcheting or freewheeling back wheel, since, as mentioned, U.S. Pat. No. 959,509 fully discloses in 1910 an available, yet unutilized free wheel mechanism, therein called a “coaster wheel” used for bicycles and other cycles, over 12 years prior to the '544 patent art.
Further, as patent '544 positions his gear to the very back of the pedals, the potential for efficiency of torque is largely lost. In contrast, the present invention positions its pedal drive system far more forward to greatly enhance pedal drive leverage and thus torque, thereby increasing the potential for speed and superior efficiency of effort, while diminishing muscle fatigue. By the proximal positioning of the pedal drive system forward, closer to the pedal arm hinge point, and by the extension of the pedals, the present invention is also able to achieve a greatly enhanced range of up and down stroke, which in combination with its previously discussed improvement of torque yields appreciably increased power and speed, while being more efficient and causing far less fatigue per amount of realized momentum.
The location of the pedal drive system is paramount, and the forward position enables the most efficient use of gravity, without which much leverage is lost. As range of motion is increased in the upward and downward thrust of the pedals, it becomes desirable for the user to remain relatively flat for reasons of slippage, safety and comfort. Therefore, by raising the pedal arm angle, the user may benefit from the additional range of stroke, while, at the same time, decreasing the incline in the peak angle of the upward stroke, and likewise, the decline angle trough in the downward stroke. '544 patent limits its range of stroke, however, as the location of the pedals are positioned directly over the frame, and at the very distal end of the pedal, thus inhibiting stroke range, especially in respect to the downward position. Such a small range of motion is disadvantageous.
Finally, by the present invention moving the intermediate transmission forward, space is made available to accommodate a gear changing derailleur of which the prior art structure precludes the space to accomplish this. Other significant improvements can be seen in the following summary, such as efficient use of gravity/leverage, thrust, speed, decreased fatigue, increased comfort, control and safety, and trick uses, over prior art.